Worlds Apart
by Soleya
Summary: An Ancient device sends Jack and Sam to a world where everything is just a little bit... wrong. Why? Can they cope with the differences? And, most importantly, can they find their way back?
1. Chapter 1

Disclaimer: I don't own anything. We all know I'm far too dangerous to actually be allowed to run rampant with the characters.

Author's Note: The science actually came from an interview with Joseph Mallozzi on the Stargate Wiki. And the philosophy came from the Jesuits. Seriously. I couldn't make this stuff up if I _tried._

Thank you to polrobin again for being an amazing beta.  


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Worlds Apart**

"This had better be good."

From beside where Jack O'Neill stood in the Gate Room, Major Carter looked over and smiled mischievously. "Can't be, sir. They say there aren't even many trees."

"Yeah, well, this is the last time I let the Marines dictate where I go," he threatened. So SG-5 had come back a few days before with reports of massive amounts of Ancient writing on a rock. Who cared?

"Jack, this is an amazing find," a voice said from his other side. "If it really is Ancient, we could learn more about them. And the more exposure I get to their writing, the easier it will be to translate."

Oh, right. Daniel cared. Damn.

"Receiving MALP telemetry," Walter announced from the Control Room. "The gate appears to be clear, sir."

Jack glanced up to meet his CO's eyes. "SG-1, you have a go," General Hammond announced.

"Great." Grumbling under his breath, he led the way up the ramp.

~/~

"Wow."

Sam grinned at Daniel – for a linguist, sometimes he gave the best, most... _concise_ descriptions. And this one was particularly apt; the valley stretched long and wide in front of the stargate, covered in a dense, scrubby grass and tiny purple wildflowers. SG-5 was right, there weren't many trees, and the ones that were there were squat and wide – evolved, she knew, to hold massive amounts of water in their trunks to survive the dry season.

The whole place reminded her of photos she'd seen of the outback, and the enormous, looming red rock in front of her did nothing to dispel that view.

"It's... it's like Uluru," Daniel managed. "Wow."

Colonel O'Neill raised an eyebrow. "Huh?"

"Ayer's Rock, sir," Sam supplied.

"Ah." The look on his face belied his words – he had no idea what she was talking about.

"The monolith, sir? It's like the one in Australia."

"Oh, right."

She shot him a smile. "SG-5 said the inscriptions were on the mountain itself."

"Well, then, what are we waiting for, campers?" Jack asked, his personality as big as ever. "To Oz!"

~/~

Daniel hadn't even quite gotten to the cliff face when he dumped his pack and began rifling through it, emerging triumphant with his notebook and video camera. Jack wished that the man's excitement was even a little bit contagious, but no such luck. And as he glanced from down each side of the rock, its face carved into a smooth surface for about the first seven feet and covered with inscriptions as far either direction as the eye could see, he knew they were in for the long haul. It would take days – maybe longer – for Daniel to document everything.

Crap.

"You think they carved on the whole structure?" Carter asked him softly. "All the way around?"

He shrugged. "Dunno. Maybe." With his luck, yes.

"I wonder if he's noticed yet that sections are missing."

The words made him look again, and he saw what she meant – over the years, water had cut small rivers into the stone, taking out a vertical strip of the writing three or four inches wide in several places. Daniel was sure to notice soon – and complain about it. "Y'know, Carter, maybe we should do a perimeter sweep."

The grin she shot him said she knew _exactly_ what he was up to. "Yes, sir."

"Daniel, Teal'c, we're gonna take a look around. Y'know, check for Jaffa, that kind of thing. And see how far this writing goes, I guess."

"Oh, that would be great!" the archaeologist exclaimed, not even looking up.

Jack ignored him. "Teal'c, keep an eye, huh?"

The alien gave a solemn nod. With a tilt of his own head, Jack prompted his second along the rough, rocky path that seemed to circle the monumental rock, falling in just behind her.

Sure enough, the writings stretched on... and on... and on. Yes, it would be days before he could get his crazy friend away from this place. And they had been walking for nearly half an hour, Daniel occasionally chattering in the radio and Carter obligingly carrying on the conversation – to save his own sanity, Jack thought, and he was grateful – when she suddenly stopped.

"This is... different."

Jack stepped back to get an overview – up close, it was all pretty much the same – and saw that she was right. Three large squares had been drawn in the stone that set off areas of the text. "Yeah? Let me guess – this is the important stuff? What does it say, 'start translating here?'"

"I have no idea, sir," she answered, her attention too focused on the cliff to really answer him. "It's not just writing. See these grooves? There's something else."

Carefully moving a little closer on the uneven trail, he squinted a little. The neatly carved squares were large, maybe five feet tall by three feet wide, and the center one seemed to contain inscriptions on a flat surface like the rest of the writings all around the massive rock. But the left and right squares contained hundreds of smaller squares, each with different symbols in them. It looked like someone had given a little kid an oversized chunk of grid paper. "What do you think they are?"

"The cuts are deep into the stone, sir, not superficial like the outlines are. I think they're.... I think they might be buttons?"

"One's missing," Jack told her.

Her gaze immediately moved to the direction his finger pointed, then shifted over to the other panel. "One's missing on each." Squatting down close to the wall to get a better view, she revised her statement. "Actually, I don't think it's missing at all. It's just... inset, and the stones next to it have... grooves. Like you'd use for drawers that don't have knobs? So maybe they don't push in. Maybe they come out."

"Wouldn't that be novel," he said dryly.

"I wonder what it does," she went on, ignoring him completely as she straightened back to her full height. "I mean, we've found some pretty neat Ancient devices before, but this... it's huge. Literally. It has to be important for them to choose this planet, this monolith, and then carve all these inscriptions."

"You think all the writing is about this thing?"

"I think it's very possible, sir."

She was in full geek mode, her gaze focused solely on the unidentifiable object in front of her. How she could really focus with her nose almost on top of it, Jack didn't know, but he let it go.

Until a hand came up from her side, and he thought with just a little bit of alarm that she was about to touch it.

"Carter, how many times have I told you not to-"

But he hit a rock in the path as he reached to knock away her hand and he tripped, failed to reclaim his balance, and stumbled into her from behind. Reflexively, he put out a hand to stop himself, and both of them fell hard into the engravings.

The moment their hands touched the wall, a bright light enveloped them.

Then everything went black.


	2. Chapter 2

Sam came to with a moan, resisting the urge to rub at the pain in her eyes. It was flash burn, sure as if she'd been welding without a helmet. And it would probably be worse tomorrow.

Though, to be fair, she thought, it could already _be_ tomorrow. The last thing she remembered....

A figure beside her groaned and rolled up to sitting, rubbing at his eyes. Yeah, his would be worse. She should probably tell him not to do that.

"What was that you were saying, sir? Something about _not touching things_?" she growled.

The colonel cleared his throat and lied, "I don't know what you're talking about."

Right. "Yes, sir. What the hell just happened?"

"Carter!" he protested. "Now, you know damn well that I was just about to ask _you_ that. Where do you get off stealin' my thunder?"

Several smart-ass answers came to mind, but the officer in her opted out of using them. Instead, she pushed to her feet and helped him up, his free hand moving to his eyes again. "Don't rub it, sir," she told him absently as she looked around.

As far as she could tell, nothing had changed. The steep cliff before her was exactly the same, engravings and all. The same scrubby green grass stretched across the valleys for as far as the eye could see, and the path that curved around the enormous rock structure toward the gate looked just as rough and overgrown as it had... however long ago that was.

She checked her watch.

Oh. Two minutes. Well, then.

"Seriously, Carter, what do you think that was?"

Why did they _always_ think she knew? "Seriously, sir," she shot back earnestly, "I have no idea."

"Huh." His fingers touched his radio to confer with Daniel and Teal'c, to see if anything had changed on their end.

Before he could hit the talk button, however, familiar gunfire ripped through the air from down the path, and both officers instinctively crouched, looking around for the danger.

"Daniel, Teal'c, report!" the colonel yelled into his radio. When he got no answer, there was no need for additional orders – Sam fell in behind him as he sprinted down the path, her fingers tight around her P90. She wished to God they were closer to the gate.

Something was terribly wrong. There were too many weapons – multiple P90s on top of a contingent of staff weapons. With Daniel and Teal'c as the only other people on the planet, there should have been only one automatic weapon besides the two they carried.

But Sam felt bad for even thinking that as they ran, as the number of Earth weapons she heard diminished again and again. If the general had sent more teams through the gate while they were unconscious, they weren't faring well. And the fact that Colonel O'Neill's repeated inquiries through the radio got no response at all didn't ease the feeling in her gut.

They rounded the last corner just in time to see the stargate shut down, the glowing blue puddle dissolving into nothing. There were only Jaffa in sight. "Cover," the colonel ordered quickly, and they ducked behind some of the taller stones.

The plain between them and the stargate stretched wide, four distinct, small groups of Jaffa searching their surroundings. None of them had come far enough across the valley to be a threat to them, but still they kept an eye on their escape path, back toward the odd device they'd found.

"_Jaffa, kree_!" one of the aliens yelled, drawing all of their attention as he leveled his staff at a smaller boab tree off to Sam's left, over a hundred wide open yards from the gate.

An arm appeared from behind the tree holding a Beretta that was all too familiar, and the first Jaffa fell. The dozen behind that one, though, only became more interested.

"That's our cue," the colonel said, kneeling to brace his weapon against the stone that covered them as he fired, quickly drawing their attention from the man behind the tree. Sam's weapon reinforced his within seconds.

Between the Jaffa's complete lack of cover and the superiority of the P90s, it wasn't a long fight. The two were on their feet and moving even as the last of the alien soldiers stumbled to his knees and hit the ground in slow motion.

"_Daniel_?" Sam cried loudly, feet pounding across the dirt at full speed toward the twisted tree and the two camouflaged legs sticking out from behind it. Why wasn't he moving? And where was Teal'c?

She rounded the thick trunk mere seconds before the colonel and skidded to a halt at the sight she found there. His own vision blocked, he nearly rammed into her for the second time that day.

And then he saw what had brought her up so short. "What the...."

The man slumped against the tree was in sore need of medical attention – a staff wound to the ribs had left the front of his uniform blackened and torn, and his knee didn't look much better. And when he looked up at her, his pained gaze read only confusion and a little bit of alarm. "Sammie? What are you doing out here?"

It wasn't Daniel by a long shot. Sam knelt beside the man – a colonel, his uniform said, and that made as little sense as the rest of it – and gently touched his cheek. "Uncle George?"


	3. Chapter 3

Daniel traced his finger along line after line of Ancient text, his nose a little too close to the wall. He really wished he'd remembered to bring his better glasses. He keyed his radio. "Jack, this is really amazing. These writings talk about a... a portal to other realms," he translated slowly. "This could be a history of the stargate! I mean, or an expanded map, or...."

Jack didn't bother to answer. Then again, Daniel really hadn't expected him to, except maybe to interrupt, so he was kind of grateful.

"There could be so much new information here!" he went on. "For me, and Sam, and... this is great stuff. Do you have any idea how much we might be able to learn from this?"

Clearly, Jack was busy. Deciding if the grass was worth chewing, or something equally vital, Daniel was certain. But he would have at least expected Sam to say something to that.

"Jack?"

Slowly, he turned to face the large Jaffa who'd been left here to watch his back. Teal'c's hand went to his own radio. "Major Carter, please respond," he said.

The silence lasted only a beat between them before Daniel's archaeological materials hit the dirt in favor of his sidearm, and he and Teal'c took off around the enormous monolith as fast as their feet would carry them.

~/~

Carter and O'Neill stepped into the Gate Room, Colonel Hammond's nearly dead weight slung low between their shoulders. 'Uncle George' was a slip of the tongue that Colonel O'Neill would not likely soon forget, but Sam wasn't sure she could ever get used to calling the man 'Colonel.'

It was also a little difficult to handle the fact that the SFs in the room immediately moved to assault position at the sight of the three of them. The battered remnants of two SG teams – likely the people who had escaped through the gate just before they'd reached the valley – just stared at them in shock.

"Hold your fire!" The familiar voice sounded a bit panicked, and Sam looked to the control room in surprise.

"_Dad_?" The two locked shocked gazes for a moment through the glass before Jacob Carter disappeared, and Sam knew he was on his way to the embarkation room. "We need a medical team in here!" she called, helping Colonel O'Neill sit Hammond, who was just going to have to go rankless for the sake of her own mental health, gently on the edge of the ramp.

"Colonel, what the hell is going on here?" Jacob asked as he rushed into the room. Jack looked up to answer, but quickly realized the question wasn't aimed at him, but at the man who shouldn't have been a colonel beside him.

"I don't know, sir," Hammond groaned, "but they saved me."

Jacob touched Sam's arm, his eyes searching hers in concern. "Are you okay?"

"Yeah, Dad, I'm fine."

"You could have been killed!"

Sam didn't quite know what to say to that. "I, uh – well, yes."

Jack decided to step in, as his second was clearly a little flummoxed. "Jacob! Buddy! Good to see ya!" he tried, but the look in Jacob's eyes when he turned to him was not pleasant.

"That's 'General' to you, Colonel," the older man spat. "And who the hell are you, anyway?"

Eyes wide, Jack shifted his gaze very slowly to meet Carter's. She shrugged. "So…" he began, "I guess this is where we give up our weapons and get dragged to a holding cell?"


	4. Chapter 4

Luckily, Jacob wasn't in the mood to throw his not-daughter into a cell, and they ended up (weaponless, of course) in the conference room, under heavy guard. Carter had already explained the alternate universe theory, and the general did not look amused.

"So… you were kidding about that not knowing me thing, right?"

Jacob shot Jack a death glare.

"He's not lying, sir." Both men spun to the younger Carter. "Believe me, I know when he's lying. I've had lots of practice." When Jacob looked at her, hurt, she explained, "In our world, you and I had some rough years, after…" She drifted off, as they never, ever mentioned the accident that had driven them apart.

"After what?" he asked innocently.

Trying to hide her anger at that, she guffawed. "Well, I guess there's comfort in knowing some things never change."

"And some clearly do," he insisted, his own irritation feeding off hers. "Like the fact that my daughter joined up. What the hell possessed you?"

She shoved herself to her feet, and the guards twitched. "I-"

"Carter," Jack warned softly. Jacob had been good to them so far, better than was probably called for – no over the top medical exams, no detention cells – and he didn't particularly want to risk their good standing over a father-daughter spat.

She pursed her lips for a second and sat back down. "I'm not going to start this argument. Not with an alternate reality you. I won't even argue this with my dad in _my_ reality."

"So where is Carter, then?" Jack asked. "Still in research?"

The older man laughed. "In rehearsal."

"For what?"

"The Philharmonic."

That couldn't possibly mean what Jack thought it meant. His startled gaze landed squarely on her, but she just shrugged. "I haven't played piano since I was ten," she defended. Okay, so apparently that was exactly what it meant. "Wait – you're saying I'm not part of the program? Not at all?" In all the alternate realities they knew of, she'd been involved _somehow_.

"You think I'd let my daughter near this place?"

"Touché," Jack put in dryly.

"And you've never met the colonel… I'm guessing Daniel and Teal'c aren't here, either, huh?"

"Who?" the general asked.

"Yeah, that's what I thought," she mused. "Then who made the stargate work? When?"

"A scientist named Rodney McKay," he said, "and several other astrophysicists." Carter swore, and her father answered with a reproachful, "Samantha."

"When?" Jack pressed.

"Two years ago. Why?"

The two younger officers exchanged a look. "Dad," she said slowly, "our gate has been functional for over six. I've been working on the project since... 1993? I think."

"As _what_?" he demanded, gaping at her as though she'd just sprouted a second head.

She drew in a long, slow breath and let it out, her hands flat on the conference table as if channeling her irritation into the lumber. She failed, and the annoyance leaked through her words. "As someone _way_ smarter than Rodney McKay, Dad."

"You mean... you're a...."

"Best we've got," Jack told him. "Which means that, as much as I hate to break up this lovely family reunion, we need to be getting back to our own reality. They might not miss me, but they'll miss Carter for sure."

"Reunion?" Jacob asked.

Carter met Jack's eyes for a split second before looking back to her father – clearly, she wasn't quite sure how well he'd take the news that he had agreed to be blended with an alien symbiote. For all they knew, these people had never even met the Tok'ra. "It's a long story," she said simply. "But the colonel's right. We brought Gen – er, _Colonel _Hammond – back through the gate because he was injured, but we need to go back to that planet. To undo... whatever it is that we did."

"Absolutely not."

Jack raised an eyebrow. "Excuse me?"

"You're asking me to send my daughter back into a war zone, Colonel. That's not happening."

Sam's forehead slammed into her palm.

Jack felt a little like echoing that sentiment, but he refrained. "Well... for one, all the Jaffa out there are dead. And two... have you noticed the uniform? You get that she's a _soldier_, right?"

"She's a scientist, apparently, Colonel," he shot back coolly.

Jack recognized that sentiment, for sure – he'd felt that way about her at first, too – but he'd learned his lesson. Quickly. "Respectfully, _General_," he answered in a tone that made it quite clear he didn't mean it that way, "you have no idea what she's capable of. She can out-think, out-shoot, and out-fight any of the men in this room."

"Thank you, sir," she said softly, not raising her head.

"So we've gotta go back," Jack told him. "The rest of our team is probably looking for us. Besides, we can't stay here. One Carter per reality – that's the rule." The one time they'd broken that rule had been... odd... to say the least.

The older man's eyes examined his daughter – the hair, the uniform, the stature – for a long time before he answered. "I'm not letting you go alone."

"Fair enough."

"It'll take a bit to put together a team. Some of my men were injured in that last little rumble."

"Actually," his second spoke up, "we could use a trip to the infirmary ourselves."

"Carter?" he asked, having no desire to let the docs poke and prod him in anyreality at all.

"Our eyes, sir." She turned to her father. "It's nothing serious, but we've got a little bit of flash burn from the activation of the device. Some eyedrops would be nice."

"Flash burn? Isn't that a welding term?" he exclaimed.

"Oh, right. I forgot. I can do that, too."

Jacob just shook his head.


	5. Chapter 5

Jack watched as his second intently stared at the blocks of writing on the stone surface, teeth worrying her bottom lip in concentration. Behind them stood the two SG teams that Jacob had claimed were his very best. SG-3 contained two Marines that Jack vaguely recognized – they were pretty new to the program – but Colonel Reynolds wasn't there.

And the other team was SG-1. And he didn't know a single face in it.

The flagship team in this reality had to be a purely military unit, though it was Air Force, not Marine. Their team leader, Colonel Hobson, was a hard-line kind of guy – no sense of humor whatsoever. The other three – all men, all soldiers – followed his lead.

Jack really needed to have a conversation with Jacob about morale. It was ridiculous to go through life completely straight-faced when what you dealt with all day, every day was... well... ridiculous. A portal made of an alien metal that could send people instantaneously to other planets? Really? Who did that?

"Carter? Whatcha think?" He'd be spared that talk if they could just go the hell home.

"Well, sir, I'm not sure. I mean, there's two panels here, right?"

Was that a trick question? "I see three."

She blinked. "Oh. Yes. But this middle section of engravings isn't made of the same square-type stones as the left and right panels. I think it's just an inscription of some sort. Instructions, maybe."

"Well, those would be nice."

"If we could read them, yes, sir. As for the other two panels.... Well, I haven't tried, because I don't want to touch it, but... do you remember those puzzles? The ones where there's a image, but it's cut into a grid, and there's a piece missing? And you have to use the empty space to slide all of the pieces around until the picture's right?"

"Let me guess – you had one with a photo of the space shuttle."

"My favorite was of a unicorn, actually, but that's really neither here nor there," she answered flatly. "But if I had to guess-"

"You kinda do," he interrupted dryly.

"Yes, sir." She continued on as though he'd never spoken at all, and Jack thought she'd been spending way too much time with Daniel. "If I had to guess, I'd say these panels might work kind of like that – that the order can be changed to change the device's settings. Of course, what those settings are supposed to be to get us back to where _we're_ supposed to be, I have no idea."

"Ah." He looked at her for a minute, taking in that open, innocent face she always had when confronted by a problem that, by all rights, she _shouldn't _know anything about. "What happens if we just touch it again?"

"There's... no way to know, sir. I mean, it would appear that everything is laid out exactly the way it was before, but without being able to read Ancient, I can't know that for sure. It could be configured wildly differently."

"Huh. Well, what are the odds this thing has a 'vaporize' setting?"

She blinked at him. "I don't think that's its purpose, sir."

"So...."

"So, the odds of that are slim. To none."

His gaze slid slowly from her to the device and back, locking meaningfully onto her eyes.

She got the hint. "It should be mentioned, sir, that there are probably realities in which this is a Goa'uld stronghold, or... or inhabited by some other massively dangerous species, or... not even an inhabitable atmosphere. We could die instantly."

"Carter," he prodded, giving her his most charming smile, "where's your sense of adventure?"

Letting out a sigh, she turned to Colonel Hardass – Hobson, Jack corrected himself. "The first time we activated the device, Colonel, we both touched it, but there was no one else around. I don't really have any idea what the range of this thing is."

"Understood," he said, his voice a short, barking tone. "Fall back."

Jack and Carter waited until the teams had moved quite a ways away before exchanging a glance. "Well," he said, "here goes-"

"Everything?" she asked wryly.

"Killjoy."

She cringed, but joined him as he stepped up to the section of the wall they'd touched before. His hand hovered just above the wall, and slowly, hesitantly, she reached out as well.

Together, their hands landed against the sun-warmed surface.

And nothing happened.

Jack glanced at his second, then back to the teams waiting in the distance, then back to her. "Well, I think it's safe to say that didn't work."

"Maybe we have to touch the other panel?"

"Oh, sure. Why not?" He trooped over to the right-most section of engravings, Carter on his heels, and they repeated the process.

Still nothing.

He was officially out of ideas, and from the look on her face, she was, too. In such situations, Jack only ever had one thing to say.

"Huh."


	6. Chapter 6

"I have to assume that there's a setting on that device that can send us back, and we know now that we can, in fact, reorganize the stones. Although, for all I know, even that doesn't do what I think it does. And even if it does, there are hundreds – thousands – of possible combinations, so there's no way to guarantee we'd _ever _find our own reality. So the device may be a dead end, and I may have to find some other way to get us back."

"You know, we found this mirror on-"

"No, Dad. We destroyed that thing years ago."

Jack O'Neill roamed the conference room aimlessly, and it was driving Jacob to distraction. Sam smiled and patted her father's hand. "He does this a lot."

"Oh."

"You know, we once had a wormhole send us back in time. I suppose it's possible that it could jump realities, as well. I'll have to think on that for awhile."

"Is there anything I can do to help?"

She sighed. "I'd almost ask for McKay, but that wouldn't do any good if he's years behind us already." She eyed Colonel O'Neill as he ducked into Hammond's – no, her father's – office.

"It can't hurt to bring him in."

She cringed. "Actually, Dad… you might hurt him."

"It's not like I haven't met the man, Sammie. He's a bit pompous, but-"

"You've never seen him around your daughter," she said with a pointed smile. Jacob's eyes darkened in anger, and she knew he got her meaning. "Besides, he's only worked in the theoretical. I've actually seen it."

"And that still boggles me," her father admitted. "Colonel O'Neill, you'd better not be snooping around in my office!"

"Me? Snoop? No!" his voice echoed from the inner room.

Jacob stood with a growl, but Sam – again – put a hand on his arm. "He's trying to help, in his own way. Though what he's trying to do right now, I have no idea."

"How in God's name do you put up with him?"

She grinned. "He's my CO, Dad."

"That scares me, Sam."

"It shouldn't," she assured him. "He's… incredibly good at his job, even if his methods are a bit…" She stopped short and got to her feet as Jack reappeared in the doorway, his face grim. "Sir?"

Jacob stood as well, surprised to see an entirely different side of Colonel O'Neill – somber, disturbed. Even in the short time he'd known the man, it was not an attitude he associated with the brash, irreverent soldier.

"Carter, I think you should sit down."

"What's wrong, sir?"

"Just… sit," he said softly.

She obeyed, and he approached her slowly. "I think I found it."

"Found what, sir?"

"The difference. The thing that sets this reality so far apart." He took a picture frame from behind his back and set it on the table in front of her.

Carter's mouth fell into a soft "o" as she took in the contents of the recent photograph. Her counterpart sat on a piano bench next to Mark, her brother. Behind them stood her father in full dress blues, two brilliant silver stars on his shoulders. And encircled in his arms, her long hair ashen and face wrinkled in a smile, stood his wife.

Jack watched, concerned, as his 2IC's chest heaved, her breaths quick and shallow as she stared at the contents of the frame. She was dangerously close to hyperventilating. "Carter," he murmured. He'd known the news would be a shock, but he was starting to think he'd underestimated the force of it severely.

She all but knocked him over as strong legs pushed back from the table, the chair tumbling, forgotten, to the ground. Shoving past them both, she ran for the door.

Of course, she had completely forgotten that they were still security risks, that they didn't belong in this SGC – this world – and two burly SF's reached for their sidearms. "No!" Jacob barked at them, and though they looked surprised, they lowered the weapons and let her pass, following immediately.

To say that the older man looked stunned by his daughter's reaction didn't quite do his expression justice. He stared openly at the door for a long moment, jaw hanging, before he moved to go after her. Jack clamped a firm hand on his arm. "Let her go."

"Get your hands off me, Colonel," the man growled.

"Jacob, listen to me. You are the _last_ person she's gonna want to see right now."

The general looked at him, pain in his features, and Jack saw that he finally got it. This Sam was his daughter – and yet, she wasn't – and he knew nothing about her. "What the hell just happened?" he asked softly.

He scrubbed a hand roughly through the hair at the back of his neck, anxious and buying time. Surely Jacob wasn't going to take this well, and not only was the colonel unsure _how_ to tell him, but _what_ – he knew very, very little. Finally, he settled for, "I don't know details. She doesn't talk about it."

"You know _something_," he pressed.

"All I know," he said softly, "is that when Carter was young, her mother died in an accident."

Even when he'd been dying of cancer or rotting in a cell on Netu, Jack had never seen Carter's father look quite so ill. Quivering hands grabbed the family image from the table and held it close. "Jeanie," he breathed softly. "But... how?"

"I don't know, exactly." He didn't. There was just one tiny tidbit he was holding back, and he had no intention of spilling it. Alternate reality or not, he considered this man a friend.

Jacob, of course, had always been able to see right through him, and that ability apparently wasn't reality-specific. "That doesn't make sense. Why would she run from me? Why...?"

"I can't really say, Jacob."

The cold stare said very clearly that silence wouldn't fly.

He sighed. There went that plan. "Because whatever happened, it was your fault."


	7. Chapter 7

It was a rule.

Jack O'Neill did not go comfort Sam Carter.

It wasn't because he wanted her to be miserable (obviously, he didn't) or because crying women made him uneasy (they always had). It was because he knew that, deep down, Carter was just as uncomfortable showing weakness in front of him as he was seeing it from her. Maybe more so.

Daniel was way more qualified for that stuff, anyway. The touchy-feely, matters of the heart crap. Somehow, he always knew what to say to her – to anyone, really – when it all hit the fan. Even Teal'c, when he deemed it important enough to say anything at all, seemed to know how to set her at ease better than he did.

So he didn't, as a rule, even try.

He had once, after she'd been taken by the snake, but he'd failed. It had made him feel a tiny bit better that everyone else had failed, too, but not a lot.

The second time, it hadn't even really been Carter. Not his Carter, anyway, and though she told him he made her feel better, he wasn't all that sure. And he sure as hell hadn't _said_ anything to make her feel that way.

And every time after that, she'd shut him down fairly quickly, resorting back to "sir" and "Colonel" and looking at him with that stony military mask that he just knew she'd learned from him. And, he supposed, from Jacob.

But not this Jacob.

And that was a problem, because this was really one of those moments where she needed somebody, and Daniel and Teal'c weren't around. And Jacob – this Jacob – didn't know her at all. In fact, not a single person on this base knew her.

Except him.

He didn't really need the guidance the SFs gave Jacob – _General Carter_ – to find her; there were only a few places he could think to look. Her lab was out, and her quarters – even upset as she was, she was rational enough to realize that they wouldn't be the same. The locker room would be his next choice for a decent place to hide, if nothing else, but he went for the more obvious (and closer) option.

Sure enough, the guards who'd followed her out of the room stood on either side of the closest women's restroom, looking incredibly uncomfortable. They snapped to attention at the general's approach, and the senior airman spoke. "We didn't think we should follow her in, sir."

"Thank you, airman."

The bathroom door surprised them all as it flew open and a sergeant stepped out, jumped in surprise at the four men hovering in her way, and came quickly to attention. "General."

"At ease."

"Anybody else in there?" Jack asked.

"An officer, sir. I didn't recognize her. She's, um.... Maybe I should get Doctor Fraiser, sir."

He winced. Great. "No. Thank you, Sergeant."

"Yes, sir." Dismissed, she slipped out from the group and hurried down the corridor.

There wasn't even a word for how much Jack didn't want to go in there, how much he wished for Daniel or Teal'c or... anybody, really, who could help her more than he could. But that person just didn't exist on this planet, and he locked eyes momentarily with her not-father before pushing open the door.

He'd been in women's restrooms before, sure, once or twice, but always for something a little less than publicly decent, and certainly never with a woman under his commmand. And never, ever on a military base. The atmosphere only served to make it all a little more awkward – and that was _exactly _what he needed, he thought wryly. For this to all be a little more awkward.

A slight crouch revealed two black combat boots sticking sideways into the nearest stall from the one past it, and he closed the distance slowly, letting his footsteps warn her of his approach. She slumped in the tiny space sideways, her shoulders and head against the open, pushed back cubby door and shins against the other divider. Her eyes, though closed, were red-rimmed, but her face was a little too pale, a little too evenly damp to be explained just by crying.

The knowledge that she'd actually been sick made him wonder if he should have told her at all. Maybe ignorance really was bliss.

There wasn't exactly a lot of room, and she didn't look at him as he squeezed his shoulders into the wall space next to her feet and slid down beside her – and in front of her, kind of, her shins against his arm and vice versa.

"Carter," he said softly, and then he ran out of words. He probably should have thought that through a bit longer before he opened his big mouth.

Thankfully, she saved him from having to find something else. "She took the red-eye." Her voice was little more than a breath, and though she opened her eyes, she looked up, not at him. In a way he was grateful, but he knew it wasn't only for his benefit – it helped keep the tiny mounds of water at the bottom of her eyes from escaping. "And she was supposed to wake me before she left for the airport, but she decided to let me sleep."

Jack was pretty sure, in the five years he'd known her, that she had never mentioned her mother – never even mentioned having one, much less actually talked about her. All he knew had been gleaned from the mission reports about the crap they'd made her drink on Netu and one long ago, very short conversation with Hammond. If she wanted to talk now, he wasn't about to interrupt.

"She was gone for six days, and I was so excited the day she was supposed to come back. I made her cookies." The tremble of her jaw gave away more than she probably wanted to, and he fixed his gaze somewhere on the dull grey metal next to her head as she whispered, "Of course, she never got to eat them."

A deep breath composed her a little, and she unconsciously mimicked his posture, hands on her knees, her gaze straight ahead. "I hated him for a long time. I forgave him. Because he was my dad, and he was all I had left. And because I knew he hated himself, too. And because I loved him, but I still hated him, you know?"

He nodded a little.

"It took me years to get over that, to stop being angry with him. And I did it. But I _hate_ him _so _much right now." The anger was fierce, but fleeting. "I didn't get to say goodbye," she went on softly. "I didn't tell her I loved her. I never got to say goodbye."

A single tear trailed down her cheek, and she dashed it away with the back of her hand. "I hate him," she repeated, the rage slowly beginning to build again. "Everything could be different. One choice – one _stupid _meeting that he just _couldn't _cut short – and everything could be so different. I hate him for making that choice – for what he took from me. And I hate _him_," she pressed, throwing a nod toward the corridor, "for _not _making that choice, and for giving _her _everything _I_ was supposed to have!" Another bitter tear escaped, and she left it. "And I know that doesn't make any sense," she said softly.

"No, it does," he assured her gently.

Two damp but grateful blue eyes flickered to his for a second, and he ever so briefly entertained the thought that he might have said the right thing for once. But he hadn't, of course; when her gaze flew back to his face a moment later, she looked horrified at what she'd just let out. Stiffening, she wiped her face and looked away. "I'm sorry, sir."

"No, Carter, it's-"

"No, it isn't. It's completely-"

"Don't you dare say 'inappropriate,' Carter."

She looked at him in shock, and he knew that had been exactly the word she was going for.

"I'm your CO," he told her softly, "and I know that makes this... complicated. But you know that I...." It hadn't been so long since that awful chair, when he'd been forced to tell her how much he felt for her, and now wasn't really the time for deep confessions. "That I would do anything to make you hurt less. And if that's not good enough for you, well... right now, I'm all you've got. And you're all I've got."

She sniffled a little and nodded.

But he was Jack O'Neill, and it wasn't going to end on that note. "And so help me, if you get up and walk out of here without me, I don't think I'll ever move again. Because I'm really, really stuck."

She laughed, and he applauded himself that he could at least cheer her up a little, if not make it all better. "That's not good, sir," she chuckled, "because I think I am, too."


	8. Chapter 8

The look on Jacob Carter's face made it pretty clear that he didn't really recognize the woman who had taken over one of his science labs. Jack twisted past him and settled the two cafeteria trays he held on the tall table, but didn't immediately interrupt.

Working, Jack thought, had helped her get past the shock and hurt she'd felt the day before. Or maybe it was the other way around – her emotions drove her to the work, enabling the unending stream of math that had come from her dry-erase marker over the last twelve hours.

Either way, Carter, when confronted by a problem she had to solve and didn't know how, was an unstoppable machine. If the stargate could undo all this, she'd find a way.

Jacob had tried to get her to sleep. Jack hadn't bothered. He had, however, brought her food every couple of hours.

"Carter."

She started as though she'd completely forgotten anyone else was in the room – in the universe, maybe – but she didn't turn around. "Yes, sir. Just a minute."

The marker went back to the whiteboard again, scrawling something neither man could even begin to comprehend. She stepped back and stared for a minute, erased something, fixed it, and stepped back again.

"Carter," Jack prompted. "Jello."

"I'm almost done, sir," she answered absently, not even glancing at them.

"And by almost, you mean it'll only be a couple more days. Come eat."

The marker stilled, though she didn't turn. "I hope it's not that long, sir. You know the repercussions of that."

Yeah, the memories of a different Carter sitting in a hospital bed while her body tried to jump out of its own skin were still pretty clear. "Well, here's the deal. I'm not eating until you do, and you know how I get when I'm hungry."

The general raised an eyebrow at him, and Jack just grinned. Yeah, he had a lot of practice with this.

"_Blue_ jello, Carter. They don't make it here. I had to request it. Special."

That made her laugh, and she finally pried her eyes from the board to look at him. "Thank you, sir."

"Now put the marker down and eat."

She thought about it for a moment – he could see it in her face. She thought about telling him she wasn't hungry and turning back to her work, but it would have been a lie. After a beat, she clipped the lid back on the marker and grabbed one of the trays.

~/~

"So, the 'portal' in these inscriptions," Daniel began, moving the projector on the conference table a little to center it on the wall. "I originally thought it meant the stargate, but clearly it's talking about this device that Jack and Sam found." The corner of one of the photos revealed a portion of one of their packs, and it made his chest clench a little. They'd found the site completely undisturbed, their abandoned equipment the only evidence that they'd ever been there at all.

"Where did it send them?" General Hammond questioned.

"Uh... I have no idea," he said. "None of the inscriptions say anything about time, so I don't think that's it. It has to do with placement – it took them some_where _else. But as to where...."

Doctor Lee leaned forward a little. "And what did the inscriptions on the control panels themselves say?"

"That's the odd part. They're just numbers. One through nine and then a base-ten system. I assume, from the way the panels are made, that the individual blocks are removable and reconfigurable. I can't be sure, of course," he added, shooting a dirty look at Teal'c, "since I wasn't allowed to touch it."

"And you won't be until we know what it does," General Hammond told him.

The archaeologist sighed. "General... the inscriptions can only take me so far. The way I see it, we have three options: we can do nothing and wait for them to find a way back, we can keep wasting time with these inscriptions, or we can figure out how to activate the device and go after them."

"Absolutely not!"

"General, they might need our help! They could be in danger!" he protested.

"Exactly," the commander pressed. "We have no idea what we might be walking into. For all we know, it could take you straight into the center of a Goa'uld mothership. I could be sending good men to their deaths in a search for two soldiers who – and I'm sorry to say this, son – might already be gone."

Daniel set his jaw. "This is Ancient technology, not Goa'uld. The odds of that are extremely slim."

"Nonetheless, they may have been transported somewhere quite dangerous, Daniel Jackson," Teal'c put in. "Perhaps even a planet that does not sustain life."

"And if they're in trouble, we're just gonna leave them there?" the younger man asked, defeated, sinking into a chair. "What if they're hurt? What if they're stuck and can't get back?"

"Then sending you out there to get stuck as well won't help them, Doctor Jackson," General Hammond said gently. "For now, I think the best thing to do is concentrate on your translations. Maybe you'll find something there that can help us more."

"The sheer amount of material.... That could take weeks."

"Then I suggest you get started."


	9. Chapter 9

"I've never seen her like this."

Jacob Carter had learned by about hour twenty-one that his daughter's work put her in a reality all her own, that the only things that existed to her were the growing collection of dry-erase boards, several colors of markers (though mostly red), and her own two hands. He'd tried to talk to her a couple of times, but she mostly didn't even hear him – and when she did, all he seemed to get were absent, one-word answers. At the moment, she was ignoring him completely, though he didn't think it was a willful thing.

"Oh, she does this a lot."

The only man who seemed to be able to get through to her at all was the rather irreverent colonel who had stepped through the stargate with her. And while his overly-familiar way of talking to the general and his complete disrespect for the Air Force was more than obnoxious, Jacob couldn't deny that Colonel Jack O'Neill cared deeply about his daughter.

Maybe a little too deeply. And he wasn't sure what to think about that.

"Define 'a lot.'"

"Anytime she can't wrap her brain around something. She doesn't lose well."

The younger man watched Sam intently, and Jacob took the opportunity to observe him for awhile. He was... casual about it all, as though he had all the confidence in the world that she would drag them out of this – or any other – conundrum. Feeling the general's eyes on him, he gestured toward the boards and asked, "You understand any of this?"

"Hell, no, Colonel."

"Huh. Guess I'd always figured she got it from you."

No, Jacob had no idea where she'd gotten such a proclivity. To be honest, though every parent wanted to think the best of their children, he'd never understood how he could produce such a brilliantly talented child. A prodigy, they'd called her. "I've seen her practice the same ten measures for hours," he said softly. "The same keys, over and over – different fingerings, different methods – until it was beyond perfect."

He nodded. "Sounds like Carter."

"But she always knew when to stop." His gaze slid back to the beautiful girl that he couldn't quite recognize as his own. "This... single-mindedness, this self-destructive obsession – giving up food and sleep.... That isn't my daughter."

Colonel O'Neill took in a long, slow breath, and Jacob realized he was censoring himself. Perhaps his brashness wasn't a lack of filter, but the filter itself, he thought – the colonel's way of avoiding what he didn't want to say. "Well," he said finally, "I can tell you that her OCD has kept me alive this long, so I don't particularly mind it. Much."

"And?"

"And playing piano doesn't exactly carry the weight of the world."

"And?"

The brown eyes that met his own were sharp, reading him, silently asking if he really wanted the answer. "This has always been inside her, Jacob," he said simply.

"But?"

Though the woman across the room was completely embroiled in her task, paying not the least bit of attention to them, he lowered his voice. She wouldn't be able to hear him even if she strained for it. "But the woman you raised – you and your wife – always knew she was loved. That she was good enough to make her parents proud." He sighed. "And _this _woman.... She can never know. So she'll never stop trying."

Swallowing hard, Jacob looked across the room again, and the colonel was right. The way her forehead wrinkled unhappily, the way she scolded herself a little too hard just before she would erase something.... His chest ached a little for this version of his daughter who seemed all at once so very old and so very, very young.

It would mean breaking just about every rule in the book, but if he could help her....

"What if she could?"


	10. Chapter 10

Jack knew Carter wouldn't be happy about the summons to the conference room – and probably even less happy about its cause. He met her at the top of the spiral staircase, knowing well the off-kilter route she always took from her lab through the Control Room "just to check on things," with a cup of fresh coffee.

"Thank you, sir." Eager hands wrapped around the mug, and she was halfway through her first sip when she saw the man sitting on the other end of the conference table.

To her credit, there was no spit-take. She didn't even choke. She just tipped the cup down a tiny bit, swallowed her coffee, and said into the mug, "This is a waste of my time."

The hard ceramic reflected and twisted her words, and Jack was pretty sure the other man didn't catch them. Jacob, however, did. "Sammie, if he can help...."

"He can't. And we're wasting time." Mug hit table with a slosh as the newcomer's eyes ever so slowly swept up her uniform, taking in every curve. He was really pushing it, Jack thought, and ordinarily he might have stepped in. His second, however, was well armed in dealing with this particular problem from this particular man. "But don't let him leave without lunch," Carter added. "I hear it's lemon chicken day."

It wasn't, and Jacob's mouth opened to correct her, but Rodney McKay pushed to his feet first, looking more than a little shocked. "I take it we've met," he said slowly.

"In two too many timelines," she retorted. "I'm going back to my lab."

"You might like me once you get to know me!" he called, and she whirled to face him.

"You're forgetting – I _do_ know you. So that's not helping your case."

"Nonetheless, he's going with you." When Carter gave her father a stare like he might as well have just hopped on the massive table and done a jig, he shrugged. "You always told Mark when you helped him with his Calculus that two heads were better than one."

The stare slowly morphed into a look of complete disbelief. "Mark _failed_ Calculus," she growled. "And you grounded him for a month and he moved out the next day. So _I_ never said that. And even if I had, it would have only been to make him feel better. It was a lie."

~/~

Rodney McKay went largely ignored – completely ignored by Carter – as he stared at the five whiteboards bleeding equations. The major, as Jack had figured, went straight back to the sixth and relatively unscarred board, working on yet another series of calculations that didn't seem to contain a single real number. Letters and exponents reigned supreme.

Twenty minutes later, when McKay finally spoke up, Jack thought him fairly fortunate to still be _alive _in their former reality, much less still working for the Air Force. He wondered idly if Carter had perhaps privately castrated the man and McKay had been to embarrassed to admit it.

"This is wrong," he said.

She turned to him like a tiger that had just located its latest prey – slowly, dangerously – and Jack seriously considered leaving just so that there would be no witnesses to what might happen next. "Excuse me?"

"This is wrong."

The red marker hit the floor with a subtle click as her hands spasmed and flexed in supreme irritation. "Can you be more specific?"

"This." He waved his hand under a line on the second board. "You've introduced a variable that doesn't, shouldn't, and won't exist. And if everything past that is based on this, you might as well erase all these boards right now."

Suddenly, Jack was glad she'd dropped the marker – it likely would have found its way into the egotistical man's eye or some place equally vulnerable. And that thought made him shift in his chair. "Carter," he soothed softly.

"That variable," she pressed, "stands for the amount of additional entropic force generated by the presence of duplicate people in one reality. And it's not wrong."

"You can't know that," he argued.

"I can't...." Swooping down to snatch the pen from the floor, she crossed the room to the second board. "I can know that. Everything from here -" she drew an angry vertical line near the start of the second board, "to here -" and another strong line appeared down the middle of the fourth board, "is fact. I've lived it. So don't tell me my math is wrong."

"You make it a habit to travel to other realities?" he snapped, obviously not happy at being pulled up quite so short.

Jack resettled against the far wall. "Actually, another Carter came to ours."

He turned back to the woman with a snort. "Another _you_?"

"Yes, another me," she shot back.

"And she suffered this... this...."

"Entropic cascade failure."

"How long did it take to set in?"

Jack was really hoping Carter would remember that one and _not_ glance his way, thus making him admit that he remembered pretty much every minute of that very strange visit. But luck had never really gone his way, and she shrugged at him. "Three days," he supplied. "Well, two and a half, I guess."

The shorter man chewed on that for a moment, irritation replaced by puzzlement. "But that Major Carter was military, too."

He shook his head. "No."

"Well... but... then how did she end up in an alternate reality?"

"She was a civilian contractor," Carter supplied. "Like you. Stationed at the SGC."

"So.... Still, that reality was much closer to yours than this one."

"Hell, yes!" Jack answered emphatically. Except for the facility itself, which had existed far before the SGC got its hands on it, hardly anything about the place was familiar.

But McKay looked oddly put off by that, and not in a good way. Both soldiers watched him for a long, tense moment as he stared at the equations before him; finally, Sam stepped away from the empty space on board number six and handed him a marker – though, Jack noticed, it was a color she had never used.

He actually recognized the first line... but only because it was a direct copy of something Carter had written on the third board. Or maybe the fourth. Everything the man scrawled after that was complete and total gibberish. Greek, even.

But not to Carter. She watched the equations take form intently, and somewhere around the fifth or sixth line her mouth fell slack. He knew that expression, and it was never good. "Carter?"

"I hadn't considered that," she said softly.

"Considered what?"

"That the amount of extra entropy generated would be proportional to the distance between the two realities."

Of course it would. "In English, Carter," he pressed.

Her eyes, when they raised to his, were troubled. "Since this reality is much further removed from ours, we can't really use what happened to Doctor Carter as a gauge for what will happen to us. It will be quicker this time. And worse."

She always had known how to kill a party, he thought as the implications of that settled in. "So... _theoretically_," Jack said, "someday we could bounce in on a reality so far from ours that we just immediately spontaneously combust?" The idea was kind of cool, in a horrific kind of way.

"I doubt there would be fire involved, sir."

He shot her a look, and she sighed.

"Okay. Theoretically, yes. But realistically, no."

"Why not?" McKay asked.

"Yeah! Why not?"

"Because any reality that far diverged wouldn't have us in it. And we already know that an alternate won't suffer the effects if their counterpart is dead."

"Ever? You know that for sure?" the other scientist asked.

"Well, no. But it certainly doesn't affect them as soon, at least."

"Then it's possible that the colonel is correct. There could, in fact, be realities different enough to induce that kind of failure, even if the problem of duplication wasn't an issue."

Jack put up a victory sign. There was nothing better than being right. Most of the time.

"But-"

Any further technobabble was blissfully cut off by Jacob's arrival. "Sam," he beckoned softly. "There's something I think you'd want to see."


	11. Chapter 11

The metal of the door was cool against her hand, and Carter stopped that way for a minute, fingers splayed against the dull gray surface. For the hundredth time in the past few minutes, Jack thought this might not be such a good idea. "If you're not ready for this...."

"How can anyone possibly be ready for this?" she asked softly.

"Maybe I should just wait here."

"No." The answer was a little too quick. "Please."

"Okay."

He watched her compose herself, sucking in a deep breath, and before she could chicken out again, she pushed the door open and stepped just inside. Jack followed her immediately, braced for anything that might happen.

Across the isolation room stood Jacob, looking almost as nervous as Carter and the woman beside him. Her wrinkled eyes took in the young woman slowly, from the combat boots up. "Your hair," she exclaimed softly, an amused smile spreading across her gentle face.

"I had to cut it," Carter breathed so softly that Jack wasn't sure the woman could hear her across the distance, "when I joined the Academy. I just didn't have time."

That was clearly not the response the woman had expected, and Jack wondered for a moment if Mrs. Carter could really have a clue who she was dealing with – that this aspect of Carter's personality had had its growth abruptly halted at the age of eleven. That she was so very concerned that this version of her mother wouldn't approve of what she had become.

The kind smile spread further. "I like it," she pressed, moving a little closer, and Jack's fears fell away. "It makes you look so official. I can't believe my baby's an officer."

If Carter took that the wrong way, she forgot completely when the woman took another step and opened her arms wide. His second flew into them, fingers digging tightly into the back of her mother's jacket as they rocked gently, the younger woman's face completely hidden in the embrace. It was only when her shoulders started shaking that Jack knew she was crying. He averted his eyes.

"Shh, baby," the elder Carter soothed. "I'm here now. It's okay."

Pitching a shoulder against the wall, Jack settled in for awhile. She had been given a gift – a surreal opportunity to interact with someone long lost. He'd gotten that too, once – more or less – and it had meant the world to him. He wasn't about to interrupt.

Too soon, though, his second abruptly pulled back, and he levered away from his support. "Carter?"

"Samantha?" her mother asked, surprised. The younger woman's hands were still clasped around Mrs. Carter's forearms and vice versa, but her entire body language had changed. Something was seriously wrong.

"Colonel," she said softly, bringing him immediately to her side. "I think I-"

Her words devolved into a choked cry as she fell to her knees, her entire body seeming to morph and shift before their eyes. Failing cells slipped from her mother's grasp as she tumbled, and both Jack and Mrs. Carter crouched beside her.

"Jacob?" she cried, alarmed. "Jacob, what's happening to her?"

He joined them on the floor, firmly holding his wife's shoulders. "I don't know."

Jack did know, although Carter was right – it was way worse than what he had seen before. Her entire body convulsed and contorted as she struggled to stay on her knees, and when the spasms ended, she nearly collapsed. One strong arm wrapped around her shoulders and pulled her into his chest, and she didn't fight him, breathing hard.

"Samantha?" Horrified tears streaked Jean Carter's face as she stared at her barely conscious daughter.

"What the hell was that?" Jacob demanded hoarsely.

"Uh...." He knew this. Really, he did. "Endemic... endermal... endo...." Nudging the woman in his arms, he prompted, "Help me out here, Carter."

Her voice was weak. "Entropic cascade failure, sir."

"Right. That."

"And Doctor Carter was right," she breathed. "That wasn't pleasant."

"_Doctor _Carter?" Jean questioned.

"What does that mean – cascade failure?" her husband pressed.

"It means," Carter answered softly, ignoring the hitch in her breath as she pushed up to sit under her own power, "that I can't stay here. The universe can't handle us both."

Jacob's hands caught her chin – gently, but insistently. "Is _my_ Sam at risk for this? Can this hurt her?"

"From what we've seen, no. Only the... the intruder," she explained, stumbling over the word, over being the one who was so wrong there, "seems to suffer the effects. But if I can't get out of here... then maybe. I don't know."

"Sweetheart," her mother whispered softly.

Carter sniffled. "I wanted more time. I wanted-"

Once again, the older woman wrapped her tightly in her arms. "I know, baby. I know."


	12. Chapter 12

Jack found Carter curled on the floor in her lab, breathing hard. The swipe of red all the way down the dry-erase board was clear evidence that she'd tried to fight it, to continue working as long as possible... and failed. McKay crouched next to her, looking concerned but keeping his hands to himself, and Jack had to wonder exactly what she'd threatened him with to keep him on good behavior while they'd been alone.

"How's it coming?" he asked softly, kneeling on her other side to put a gentle hand on her shoulder. Guilt ate at his stomach – he shouldn't have left her.

"Not good, sir," she panted. And then, "I never expected this."

"Expected what?"

She pushed up to her elbows, but kept her head toward the floor – to stave off a dizzy spell, he guessed. "That the effects could vary from person to person. Maybe it's not the difference between the realities that makes this happen – it's the differences in our individual selves. It's the only reason I can think of for why you haven't been hit yet."

Jack was pretty sure that wasn't it, even though they still weren't to the hour threshold where Doctor Carter had begun to spazz out. Maybe Carter couldn't think of another reason – maybe she didn't _want _to – but he could. And the look on McKay's face mirrored his own. Before the man could open his mouth and make things worse, he shook his head slightly at him.

_Don't say it._

"Uh... right," McKay muttered. "That must be it."

"Any news?" she asked.

"No. I asked for anything else they might know about alternate realities, but they've got nothin'. And they don't even know the Asgard."

"The who?"

Both soldiers ignored the man.

"It's amazing they're still alive," Carter breathed. She tried to push herself up a little, and Jack pulled her to sitting.

"Well, I think they just haven't had a chance to really piss people off yet."

"Sir, what if this starts to affect our counterparts? What then?"

"I don't know." Apparently, no, she really wasn't considering that other option. "Teal'c told me once that ours is the only reality of consequence."

"Yeah, but that was when we were _in_ our reality. This is theirs. Don't they get to take precedence?"

"I'd say yes," McKay put in. "Then again, I'm not the one in danger, I suppose."

"If you're even suggesting what I think you're suggesting, Carter, there's no way," he shot back.

She sucked in a breath. "Sir, if it comes down to them or us, I won't fight that battle. I'd eat a bullet before I'd tear this family apart."

He grimaced. "Yeah, I know. But we're not there yet, huh?"

"Yeah, sir," she answered with a grim nod, "we're there. This math goes nowhere. The stargate can't send us back. Not without months and months of work."

"Okay, then we're back to that device."

She shook her head. "But we tried that. It didn't work."

"We didn't try moving the stones. Carter, we don't necessarily have to find _our_ reality. If this is gonna kill you, then we just have to get out of _this_ one."

"And find one where neither of us exist!" she insisted.

"What if we don't?" he pressed. At her confused look, he said, "Look. You know I don't get this stuff. But the... failure... thingy... is caused by entropy within the forces of _this_ universe, right? _This_ reality?"

"Yes, sir. We think."

"So even if we end up in another reality where we're still doubled, isn't there a chance that this will all reset? That the entropy degradation thing will start over?"

Her eyes shifted as she considered that. "I... suppose it's possible." A secondary nod from McKay confirmed it.

"That would at least buy us some more time, right? Stop this for awhile?"

"I, uh.... Maybe."

"Then we have to make that thing work. We have to go back."

~/~

It took a few hours and two more convulsive fits before Jack took Carter's elbow to guide her up the step to the ramp. On her other side, Jacob did the same. "Dial the planet," the general ordered, and the gate began its slow sequence.

Beside him, Carter took a long, slow breath and expelled it between pursed lips. It had to be hard to walk away from the thing she'd wanted for two decades, he thought. If the natural forces of the universe weren't forcing her to do it, he wasn't sure she would. And that idea was more than a little scary – for him. He gave her arm a squeeze.

The stargate exploded to life, and SG-1 and SG-3 crowded closer behind them, waiting for the general's signal. But before they could move, one of the blast doors slid open, and Jacob turned back.

"I told you to go home," he said as his wife stepped into the embarkation room. "You're not cleared to be here."

She smiled. "But you gave George command first, and he's an even bigger softie than you are. Especially on painkillers."

Jack couldn't hold back a chuckle at the only woman he'd ever seen who could effectively neutralize Jacob Carter. The soldiers just off the ramp looked away, hiding their own grins.

But beside him, Carter was tense. He firmed up his grip on her arm as Jean Carter approached, cutting confidently through the heavily armed men, and stopped just short of the ramp. "Time may be relative," she told her daughter softly, "and apparently, space is, too. But some things never change. In any reality, anywhere, you're my little girl. I love you. And I'm so very proud."

Sniffling softly, Carter nodded.

"Now go," her mother answered, clearly fighting her own emotions, "because I can't watch you have another one of those fits."

Both men turned to the younger woman, unwilling to be the ones that broke the moment. When Carter finally spoke, her voice was little more than a whisper. "I love you, too, Mom."

And then – before she could lose the courage, Jack thought – she turned out of their arms and marched up the ramp.


	13. Chapter 13

"Seriously, how hard can this possibly be?" Colonel O'Neill paced between the two control panels in annoyance. "We didn't even _do_ anything the first time!"

"We've been lucky, sir," Sam spoke up from the spot she'd claimed in the dirt – it allowed her to use a smaller stone as a backrest while remaining within arm's reach of at least one panel of the device. "We've figured out dozens of these devices when by all rights, we shouldn't have."

"If you're saying our luck's got to run out sometime, Carter, you're wrong."

She sighed. "Okay, I won't say that. But I sure as hell wish Daniel was here to translate this."

"Wishing me away, now, are you?" he asked pointedly. "That's not very nice."

"That's not what I-"

She stopped short mere seconds before the convulsions hit again, the phase tremors tearing through her body. She wanted to scream at the sensation – every cell in her body was tearing apart, degrading without permission. Though she could sense her father at her side, there was nothing he could do; in the last few occurrences, his hands had passed straight through her arm.

It was a shame, too, because this was one of those very few times when she wouldn't have complained about being held like a child.

Finally, the fit subsided, and she dashed agonized tears from her cheeks as her dad pressed his lips softly to her temple. "I'm sorry, Sammie."

"It's not your fault, Dad," she breathed.

"They're getting too frequent," he said softly, and she nodded. It had only been maybe half an hour since the last one, and as they increased in frequency and intensity, she could almost feel the physical changes – her heartbeat was a little too fast, she felt a little lightheaded, confused, all the time. She'd thought for sure that the entropy itself would kill her, but she was starting to wonder if her body would hold up until then.

In another life, another circumstance, she would have loved to do the calculations on it – the proportionality of the entropy created to the proximity of the alternate universe. And not just that – to the proximity of the individual person's fate within that universe. But she felt... fuzzy. Off. And she knew her usefulness was fading with every spell.

When she finally raised her eyes, Colonel O'Neill was staring down at her from the second panel of the device. Perfect, healthy, Colonel O'Neill.

She had to wonder how he could possibly look so calm. This was coming to him, too, if he couldn't make the device work, and Sam knew from experience that watching someone die a horrible, painful death when she'd known it was coming to her next was a disturbing thing. But she was glad for the delay – at least it meant one of them was still able to function. "Sir-"

A bright flash of white enveloped the plain, and when it faded, Daniel and Teal'c stood between the other two members of the real SG-1.

"Wow," Daniel said. "That was bright."

Sam rocketed from her place on the hard dirt to place herself in front of Teal'c as eight P90s leveled on him. "Hold your fire!" she cried, the colonel's and her father's voices echoing her own – one out of understanding, the other from sheer terror that his own men might accidentally mow down his daughter.

Her own adrenaline level dropped with the automatic weapons, and she slumped, saved only by Teal'c's massive arms around her waist. "Major Carter, are you injured?" he asked gravely.

"Kind of," she admitted, her head back against his shoulder. "But they're friends."

"What the hell is going on?" her father demanded. "Who are these people?"

"Ah. Well," Colonel O'Neill stepped in, "this is Daniel Jackson. He likes rocks. And old things. And that guy is Teal'c."

All three men shot him a withering look. Sam just sighed. "Dad, Daniel is our linguist and archaeologist. And Teal'c... was the First Prime of Apophis, but he joined us. He's saved us dozens of times."

"He's a Jaffa!" her father protested.

"I believe that the Goa'uld are false gods," Teal'c answered woodenly, and Sam rolled her eyes a little at the familiar words. "They are a common enemy."

Daniel broke the standoff, holding out a hand to the older man. "Hi, I'm Daniel," he greeted. "And you're... still a general," he added in mild surprise.

Jacob bristled a little at that. "What else would I be?"

But the archaeologist avoided the question and turned to Sam. "And that would make General Hammond...."

"A colonel," she supplied weakly.

"And Jack?"

"Suspiciously absent."

He blinked. "And you?"

"Even more absent," the colonel put in. "Though not suspiciously."

"So I'm guessing I'm not around, either."

"Nope," he snipped. "But we're glad you're here, Danny Boy, because we need to get back to our own world before Carter's molecules spread between here and next Tuesday."

She watched as the two men exchanged a meaningful look. Daniel's eyes drifted to hers, then back to Colonel O'Neill's before he spoke. "Ah."

She had the terrible feeling she was missing something in that look, but her discombobulated brain just couldn't piece it together. With her father's help, Teal'c lowered her gently to the ground, and she settled against the back rest.

"Well," Daniel said, "this device claims to be a 'portal of the realms,' and it, as you've no doubt figured out, works something like the quantum mirror."

"Which had a handy dandy remote, as I recall," the colonel said.

"Yes. All this one seems to have are two numeric keypads, of sorts. Which I see you've completely rearranged – or were they this way when you go here?"

"Oh, no, that was me."

"I see. How many times have I told you not to touch the artifacts, Jack?" Before the other man could find a witty response, Daniel pulled two large photographs from his bag and started to reconfigure the stones.


	14. Chapter 14

It had never been more clear to Jacob why he hadn't wanted his daughter to join the military. Even with eight of his own men behind him – men who were supposed to respect him, men whom he'd firmly trained to think he was a no-frills hard-ass general – he had known there would come a point where the soldier side of him would lose out to the father.

That moment had come twenty minutes ago, when the last fit had left her too exhausted to even hold up her head. Tenderly, he stroked the blond hair in his lap, willing her some of his strength. "I wish I could take the pain away," he murmured softly.

"I know."

"I can't.... Sammie, I can't watch you die."

She forced a weak smile. "Won't come to that."

"How can you be so sure?"

"Five years," she breathed. "Haven't died yet."

"On the contrary, Major Carter," Teal'c's calm baritone sounded from a few feet away. "By the medical definition, I believe you have died many times these past years."

Jacob couldn't help it; he tensed, drawing his alternate-reality daughter a little closer to him.

"Thanks, Teal'c. That was helpful," she muttered.

The strange man just nodded slightly. Jacob had been taking in his mannerisms for the last hour or so – his, and the way the archaeologist and Colonel O'Neill bickered like brothers, and the concerned looks they all kept shooting at his daughter... and he had to ask. "What is it that you do, Sammie? With an archaeologist, an alien, and... _him_? That you're cheating death all the time? That you can take this all in stride?"

She grinned at him – it was listless, but still far more mischievous than a mere smile. "Dad," she said softly, "we're SG-1."

This was one of those moments, he was certain, where Jeanie would have warned him that a change in the wind would freeze his face just the way it was forever, and she'd be stuck with an ugly husband. He'd been shocked by his daughter's military uniform, her scientific mind.... With coaxing, he'd been willing to believe (somewhat half-heartedly) that she was good at both. But SG-1? The flagship team? "But...."

"Think outside the box, Dad. It's good for you."

Yes, that was definitely his Sam – her mother's child. A smile spread across his face. "I'm proud of you."

"All right, we're set here," the other scientist – Dan? Danny? – announced, and Jacob slid carefully out from under his daughter, allowing the Jaffa to assume her care.

That was hard to watch.

His men backed off (as did he, with a heavier heart than he'd expected), but not so far that he couldn't hear Colonel O'Neill announce, "I hate to tell you this, Daniel, but that looks a helluva lot like it did the first time we tried it."

"Well, if at first you don't succeed, Jack," the other man shot back. "It's set up exactly like the one in our reality. That should program a bridge between the two."

As one, the four reached out gingerly and pressed their hands against the wall.

And as every time before, nothing happened.

"Well, that's not right," Daniel said.

"Perhaps this device is malfunctioning," the Jaffa suggested.

Sam groaned, and Jacob was just close enough to barely make out her words. "I hope not. 'Cause I won't live long enough to fix it."


	15. Chapter 15

Jack had long ago abandoned his post pestering Daniel to move closer to his 2IC. As grateful as he was that Jacob was there to comfort her, it wasn't enough – he needed to touch her, to be close to her.

The device hadn't let out so much as a hum, and Jack was starting to think that Teal'c was right – the one on this end was broken. They had, in essence, gated to a planet without a working DHD, and they were stuck.

And the one person who could most likely pull them out of that lovely conundrum lay still, pale, unmoving. Despite her father's urgings, she hadn't opened her eyes in close to an hour – not even when the phase tremors took her again and again.

"Daniel."

Jack jerked back a little as her eyes flew open, glassy and unfocused, and she tried to sit up. He'd seen it many times – a moment of lucidity right before death – and it made his chest clench. Still, whatever she wanted. "Daniel," he called, helping Jacob support her a little.

"Yeah?" Seeing Sam, he ran over and crouched in front of her, taking the hand she waved wildly at him. "Sam?"

"The stargate doesn't know where it is," she gasped, the words badly slurred.

Okay, so maybe lucid wasn't quite the right adjective. The younger man's wary gaze wandered over to catch Jack's, and he knew he understood. These were the utterings of a crazy woman.

"It's okay, Sam," he soothed. "The stargate is fine. It's okay."

"No!" she insisted. "You have to tell it. It doesn't know."

Slowly, his head tilted, his face morphing into that look he got when he was deeply, deeply considering something. "Daniel?" Jack asked softly.

"Reverse the symbols."

Once again, Jack tried to meet his friend's eyes, but the other man was deep in thought. Forcing a small, comforting smile, he began, "Carter, if this is like that 'reverse the polarities' thing I'm always hearing-"

"Sam, you're brilliant," Daniel interrupted suddenly. Without no further explanation, he leaped up and ran to the cliff face, rearranging the stones with a speed and confidence Jack hadn't seen in him before. Carter slumped back into Jacob's arms, spent.

"Daniel?" he asked again.

"The stargate doesn't know where it is, Jack. You have to tell it."

"Yes, I heard that!" he grumbled. "What does it mean?"

"All gate addresses are the same, right?" he asked.

Jack was pretty sure that was a trick question, but Daniel never turned away from the device, pulling and replacing blocks, so he couldn't be sure. "No?"

"Yes. Six points and a point of origin."

"Indeed," Teal'c agreed, clearly – well, not clearly – as flummoxed as the rest of them.

"So this device is the same. It can't know how to get where it's going unless it knows where it's coming from. It won't work without a point of origin, just like the stargate won't."

The words tumbled out faster than a human should have been able to produce them, and Jacob figured them out first. "But how the hell can you know what the point of origin is supposed to be when there's a hundred thousand different possible configurations?"

"Easy!" he exclaimed. "It's what brought us here. This whole device is like a... a... Christmas gift tag – one side is from, the other is to. All I have to do to get us back where we came from is-"

"Reverse the symbols," Jack and Jacob said, echoing Carter's words from a moment before.

"Exactly. Put the configuration from the right-hand panel into the left and vice versa. One is our reality; the other is this one." He stepped back from the device and double-checked his photographs. "Done."

"You're sure about this?" Jacob asked.

Daniel blinked. "Well, no. But Sam's rarely wrong about these things."

"Especially under pressure," Jack agreed.

"I do not believe we should delay." The Jaffa bent and effortlessly scooped Carter's limp form into his arms, allowing Jacob to get to his feet.

Which reminded Jack of one last thing. "Jacob," he said softly, "keep an eye on your health, huh?"

"What?"

"Just... get checked. Stay on it."

He knew by the look on the elder Carter's face that he didn't quite understand, but he nodded. "Colonel O'Neill," he said, his voice just as solemn, and then he corrected, "Jack."

Jack smiled at the stiff man's use of his name. "Jacob?"

"You keep my little girl safe."

The smile grew. "Hell, I promised you that years ago."

It took only a few seconds for Jacob's crew to fall back a bit, and SG-1 stepped up to the device. Jack took one of Carter's hands, tangling his fingers in hers from behind to keep it open, and together, each pressed a hand to the wall.

This time, Jack was smart. He closed his eyes.


	16. Chapter 16

Teal'c lit the last of the candles in his quarters and settled cross-legged onto his mat, carefully slowing and deepening his breathing as he stared into the dancing flame before him. Kel-no'reem would come easily this day – a welcome reprieve from much of the last week. Meditation was always more difficult when his companions were in danger.

His eyes had no more than slipped closed, however, when a knock on the door interrupted him.

"Enter," he called, not moving from his comfortable place on the floor.

Very slowly, the door cracked open just enough to allow a slight brunette entrance. She gave him an uneasy smile. "Mister Teal'c?"

"Nurse Goodwin. How may I assist you?"

"Um... well.... It's just that, um, Major Carter is...."

Any sense of relaxation gone, the Jaffa rose swiftly to his feet. "Is there a problem?"

"Well, no. But she seems... upset... all of the sudden. And Colonel O'Neill finally left just a little while ago to get some sleep, and Doctor Fraiser and Doctor Jackson have gone home for the night, so I just didn't know who...."

"I will return to the infirmary with you immediately," he assured her. Candles all but forgotten, he followed her swiftly from the room. Major Carter had certainly not been herself since her return from the alternate reality, but she had not spoken of it, and Teal'c of all people would be the last to press her. But she rarely openly revealed distress; if her nurse had picked up on it, she could surely use a friend.

Her bed was furthest from the entrance to the infirmary, and he approached her quietly, taking in her damp cheeks and red eyes. A spiral notebook sat in her lap and she stared at it for a moment, wrote something else, angrily crossed out a large section, and started again.

Silently, Teal'c took up his usual position just off the foot of her bed. It soon became clear, however, that she hadn't even noticed him – he took that as testament to her unsettled state of mind – and he stepped a bit closer. "Major Carter."

She started a bit, deftly brushing the tear tracks from her cheeks as she looked up. "Oh, hey, Teal'c."

"Are you well?"

"Yeah. Yeah, I'm fine."

That was clearly not true, but he wouldn't push the issue. Giving a stoic nod, he shifted his weight and settled in for awhile, content merely to comfort her with his presence. He knew, though, that she wanted to talk – the Tau'ri usually did – and that even without words of his own, his presence would spur her to it. It always did.

"I just can't make it work," she said finally.

He couldn't be certain what she meant, so he said nothing.

"It should work," she went on after a moment, sniffling softly as she stared down at the notebook in her lap. "There has to be a way, but I just can't find it. No matter what I do, I get a null result. It's just not possible. But it _has_ to be. I can't.... It has to be. And I have to prove it."

Never had Teal'c seen his friend get so upset over math without someone's life being at stake. It was disconcerting. "What is it that you attempt to prove?" he asked.

"That he-"

Suddenly, she caught herself, as if she'd been about to reveal more than she really wished to, and rephrased. "McKay already showed me that the additional entropy generated in another universe is related to the distance between the two realities – to how different they are. I get that. But I thought that maybe... maybe the difference in our individual lives matters, too. That some could be closer than others. That the cascade failure could affect people differently, even if they're from the same reality."

He couldn't be sure what to make of that – what it meant or how it related to her distress – but he could only assume that 'he' meant O'Neill. "But that is not the case?"

She shook her head. "Not according to the math. But it has to be. There's a way to make it work, Teal'c. I just have to find it."

Perhaps he couldn't remove the root of her distress, but he _could_ take away what she currently fixated on – the equations. Stepping up to the side of the bed, he put a hand on the notebook and gave it a gentle tug. As he'd expected, she put up only a token amount of resistance before yielding it to him. "You must rest, Major Carter."

Still, she didn't look up. "I think I knew," she whispered, staring at the space where the book had been. "I think I always knew that it wasn't right – that I was searching for an explanation that didn't exist. But I couldn't think that he.... It can't be. It's just too much."

"Major Carter," he interrupted gently, wishing for a way to better comfort his friend, "whatever may have befallen that reality, it is not your own. You have safely returned to where you belong, and all is as it is supposed to be."

For the first time, she met his eyes. Though he couldn't be sure exactly what she sought there, he held her gaze, offering her a gentle smile.

"Thanks, Teal'c," she said softly. "I just wish I could believe that."

Usually, he was good at pinning down what was bothering his friends, but he had apparently failed. Abruptly, he switched tactics, though he knew well that the equations wouldn't change merely because she wished something to be true. "You are quite fatigued. Perhaps there is an error in your math that you can reconcile once in a more coherent state of mind."

Her expression read clearly that she didn't think so, but she said, "Yeah. Maybe." Still, she slid further down the pillow and pulled the sheet up to her neck.

He didn't move.

"You don't have to stay," she murmured.

"I am aware," he answered. But he would, anyway.


	17. Chapter 17

Sam spent two days in the infirmary after that, Janet having told them something about her organs showing signs of severe stress. Exactly what that meant, Daniel wasn't sure, but his teammate had been absolutely wiped out, so it was probably for the best.

But now that she was awake and somewhat closer to her normal self, something had been bothering him. He snatched a cup of blue jello from the cafeteria and headed toward his teammate, unsurprised to find Jack already there.

Yes, Jack always hovered over her a little when missions went wrong and she ended up stuck in the infirmary... but he usually made a show of leaving her alone as soon as Janet pronounced her fine. The archaeologist was pretty sure his friend worried about the impropriety of it all, but somehow that didn't seem to be an issue this time. And that gave him the unsettling feeling that there was more to their little escapade than either of them were telling him.

"Hey," he greeted the silent pair.

Jack looked up from his yo-yo and gave him a nod.

"Hey. Oh, thanks." Seeing the blue confection he held, Sam set her laptop aside to take it from him.

"How are you?" he asked, sinking into the chair opposite Jack.

She shrugged. "Just tired. Janet's letting me go later today."

But there was more to it than that, he knew. She radiated more than fatigue – she was tense, down. When he and Teal'c had first arrived in the alternate reality, he'd chalked it up to the entropic cascade failure – but the physical effects were fading, and her strange, closed-off temperament was not. "Well, that's good."

"Yeah," she said simply.

Jack had long gone back to his yo-yo and Sam half-heartedly turned her attention to the jello, leaving Daniel to watch her awkwardly. After a moment, he said, "So, I've been thinking."

"Uh-oh," Jack put in.

Daniel shot him a dirty look. "There's just one thing I don't understand about all this – the realities and all."

Sam instantaneously aged about five years and set her jello aside. Neither thing quelled Daniel's suspicions about the past week. "What do you want to know?" she asked softly.

"Well... that device was built by the Ancients, right? Thousands and thousands of years ago."

"Right."

"And you've told us that realities diverge with every choice we make, so theoretically there are millions of them. So it makes sense that the device had such complicated control panels – it needs that many options."

"So?"

"But the two realities – this one and the one you went to – can't possibly have diverged that long ago. It has to have been within our lifetimes."

He didn't miss the way her eyes drifted over to Jack's before settling somewhere on the bed near her IV. "And?"

"I just don't understand how a device could be calibrated for something that hadn't happened yet. That they couldn't even know _would_ happen. And that has to be true for it to work as it does, and for you to have known how to fix it, so I figured I'd ask you."

"Oh," she said, seeming somehow mildly relieved. What, he wondered, had she thought he was going to ask? "How much do you know about theology, Daniel? And the problem of free will?"

He raised an eyebrow. Of all the answers he'd considered, that one had come clear from left field. "I know that... some Christians think there isn't any free will because of the prophesies."

"Right. That Judas didn't have a choice. That he was predetermined to betray Jesus and therefore had no choice but to end up in Hell."

Daniel blinked. "Okay. Determinism. Like the Calvinists." The theory was more than a little upsetting – that a person couldn't choose whether they were good or evil.

"Yes. But there's another school of thought on that, too. What if we do have free choice, but God – an omniscient being – knows all the possible choices throughout time, but since He knows everything about us, He knows which decision we'll make?"

"Uh...." Daniel had always studied religions as a part of their respective cultures, but he'd never considered himself a particularly spiritual person. "Somehow I find an omniscient, omnipotent being hard to reconcile with what we've seen, Sam."

She shook her head. "Omniscient, omnipotent, _and _wholly good, but that doesn't matter. Just follow the philosophy."

"Okay," he agreed slowly, and was a little bit surprised to see that even Jack was watching, interested, the yo-yo dangling free and unattended.

"Both of those arguments assume that there is only one timeline, only one outcome from every choice, and you and I both know that that isn't true – that every possible result can actually happen simultaneously as the breaking point for a new reality."

"So you're saying that a truly omniscient god who could know all the possible choices for all of time could also understand all of the resulting realities? And exist in them all simultaneously?"

She shrugged. "That much doesn't matter. What I'm saying is that the philosophy exists to support the idea that someone at the beginning of time could know every possibility and therefore every reality. And even give them all a designation to sort them out – for his own purposes, if nothing else."

"And you thought about all of this while you were _dying_?"

"Of course not. I'm just saying it's possible."

"Ah. And where the hell did you learn all this?"

"CCD." At his totally blank look, she added, "Catholic religious ed."

Jack straightened a little in his chair, yanked up the yo-yo, and set the whole contraption on the table, forgotten. "But there must be millions of these realities."

"Yes, sir. Trillions, probably, already. And into the future... an infinite number."

"But that device can't handle that. Thousands, maybe. But nothing like that could handle an infinite number."

She blinked at him, surprised. "Well, no. There will always be a limitation to how many different combinations there can be, whether the control panel is made up of thirty stones or thirty thousand."

Suddenly intent, he leaned forward, elbows perched on his knees, and sought her gaze, waiting until she looked at him to continue. "So somewhere, some_time_, somebody had to decide which realities to include. Which ones were important. Knowing _everything _that would happen within them – including how they would interact."

Sam held his gaze for a moment longer than Daniel really thought necessary, then swallowed hard and looked back at the bed. "Theoretically, sir... yes."

Yeah, Daniel thought. Whatever he'd missed, it was big.


	18. Chapter 18

"Pepperoni?"

"Gross, Daniel."

It was customary for SG-1 to shuttle their own injured home and settle them in, so dinner and beers at Carter's that night (the beers were usually reserved for the uninjured, but she had certainly downed a few already) was just expected. Jack had debated telling Daniel and Teal'c about exactly what they'd found on the other side of that device and decided not to, but watching the younger man wheedle Carter continually, poking and prodding, he thought maybe he'd made the wrong decision.

"There's a slice of Teal'c's anchovy left."

"Don't even come _near_ me with that!"

Though, to be fair, he couldn't be certain whether Daniel was actually searching for information or just trying to cheer her up. He was a bumbler like that – no sense of stealth at all. And Carter's need for some cheer was pretty apparent. Teal'c took yet another empty beer bottle from her, and Jack wondered idly if anyone was counting. Was that number five? Six?

"Y'know, I heard on the news once that somebody actually decided anchovy would be a great flavor for ice cream. What mom would feed their kid that?"

"Daniel." Jack had been trying to stay out of it – just to make it clear to Carter that he wasn't hovering, that she could do whatever she wanted, but the archaeologist was getting a little close to home, even if he didn't know it. He caught his eye, and the younger man shut up.

Unfortunately, that plummeted them into that same kind of awkward silence Daniel had found in the infirmary earlier that day. There was no "safe" conversation topic, so there just was no conversation. Only Teal'c and Carter didn't look bothered by that. She, he knew, was bothered by something else entirely.

Finally, when Daniel's nervous energy reached the explosion point, he asked miserably, "You just want us to leave, don't you?"

Jack didn't miss the wince on her face as her blue eyes flew up to Daniel's glasses, then sank back to where her fingers twisted in her lap. "No," she said softly.

"You don't have to lie, Sam."

"It's been a long couple of days," Jack put in.

She nodded. "I just.... I'm pretty tired, Daniel," she told her hands. And pretty drunk, but Jack knew better than anyone that the alcohol only enhanced what she already felt, so it wasn't helping. Maybe they should have cut her off a while ago.

The other scientist's eyes found Jack's, and he gave him a small, reassuring nod. He wouldn't let anything happen to her.

"Okay. Come on, Teal'c, I'll take you back to the base."

She didn't move from the couch as they gathered their things, so Jack let them out. He had no intention of leaving, whether she wanted him to or not – he'd seen the effect this mission had had on her first-hand, and he wasn't going anywhere until she'd dealt with it all. At least a little.

He made his way back to the living room just in time to see her head out of it, moving a little less than soberly toward the kitchen. He caught up to her as she emerged from the refrigerator with yet another beer and confiscated it easily. "That's enough, don't you think?"

She shot him a plaintive look – the one up from under her lashes that he loved so much. But she wasn't happy. "So it's okay for you to drink yourself into oblivion, but not me?"

He took a sip of her beer. "The thing about oblivion, Carter, is that it doesn't solve anything."

"Never stopped you, sir."

"Point. But you deserve better."

She shook her head and meandered off toward the living room, perching on the arm of the couch and staring over its back into the blackness out the window. He watched her for several minutes before following. "Penny for your thoughts?"

"They're not worth that much, sir."

He settled into an armchair across the room with the stolen beer, content with the silence for the time being. He was almost done with the bottle before she spoke. "You knew, didn't you?"

Maybe he should have left her with Daniel. He'd successfully avoided this conversation the whole time they'd been out there, only to get stuck with it now? "I don't know what you mean."

"That whole thing about the entropy being based on the individual, not the reality as a whole? I wanted to believe that, but it wasn't the case. And you knew."

"I dunno. McKay seemed to think it was possible." Under duress, but she didn't know that.

"I understand now," she said slowly. "Catherine Langford probably retired long before McKay figured out how to work the gate, so Daniel was never brought in. And without that first mission with Daniel, they never met Teal'c. That all makes sense. But you...." Piercing blue eyes locked onto him in the reflection of the window, her expression somber, and he was certain about one thing – he really should have run away when he had the chance. "You were dead. And you _knew_. And I don't understand that."

He shrugged. "I didn't know anything for sure."

She whirled to face him, the alcohol nearly knocking her from her seat. She slid down into the couch and stared at him. "Don't lie to me, sir," she said, and he couldn't be certain whether the tinge in her voice was anger or sadness. "You were so calm. Too calm for what was coming. And every time we talked about it, I talked about _us_ and you talked about _me_. Because you knew it wouldn't happen to you. Because you knew...."

His eyes met hers evenly, and he hoped the warning there was clear. "You don't want to go down this road, Carter."

"I have to, sir," she said softly. "I have to know."

"Without the Abydos mission, I would've gone back into black ops." She wasn't going to back down, and he couldn't very well tell her the truth. "Probably died somewhere in the Middle East. South America, maybe."

The blonde head hit the back of the couch with a soft thud. "That the best you could come up with, sir?"

"It's what you're gonna get, Carter."

The eyes pinned him again. "What could possibly be so bad that you won't tell me?"

That he'd done it himself? That in that universe, without her, he was a complete and total failure with no hope of redemption? That was pretty bad.

Of course, she hadn't gotten off particularly lightly this time, either.... If she needed a reason to dislike that timeline, he had a good one. He finished off the beer and set it down a little too quickly, missing it as it tipped and rolled onto the carpet. Neither paid much attention to it.

"When they came for me," he started slowly, then added, "General West. The first time." He couldn't look at her; he needed to do something. The beer bottle ended up in his lap as he carefully dissected its label, shredding it. "It wasn't long after.... It wasn't long after the funeral."

He could hear her sharp intake of breath, and he knew he didn't have to tell her that he meant his son. He didn't look up from the bottle. "I was sitting there when they came, on his bed, with my gun in my hands. The gun that killed him. And I was gonna end it. But when they came....

"The guy who led the Abydos mission was never supposed to make it back. That's why they picked me, and why I went. I figured… shooting myself would just piss Sarah off more, but the mission…. I could die a hero. Full benefits. One way or the other it'd be better for her. So I agreed, and I stepped through that gate… and everything changed."

In the other reality, without Carter to make the gate work on schedule, there had been no mission. No one had bothered to interrupt him, and – maybe not that day, maybe not the next, but soon after – he'd given in to the guilt and the depression, and the gun had taken a second life.

As far as he could tell, the universe wouldn't let her have it both ways. Without Carter's mom in the picture, she grew into a strong military woman, SG-1 in tow. With her alive... everything changed. And barring further interruption in his own life... he ended up dead.

The beer bottle destroyed, he finally met her eyes, unsurprised to find them damp. "You saved my life, Carter. You couldn't know it then, but you did."

They sat there in silence for the longest time, and he knew she understood it, too. No matter what, Jack O'Neill and Jean Carter couldn't both be part of her life.

Finally, Sam asked, "So can I have that beer now?"

He chuckled and shook his head. "No."

"Damn." She settled back onto the arm of the couch, staring at her hands. "It's just not fair."

"Yeah, well, life's not fair. No more beer for you."

She shook her head. "I didn't mean the beer."

"Oh."

Long legs pulled up in that manner he'd long attributed to her – one leg tucked beneath her, the other knee tight under her chin. The posture always made her look small, like a little lost child, but this was the first occasion for which Jack actually found it fitting. A little lost child – she kind of was.

Her voice was thin, and he didn't think it was from the awkward position of her chin on her knees. "I didn't just lose her. Within a couple of years, I lost Mark. And then Dad was pretty much gone. Or maybe that was the other way around; I don't really know.

"We'd been close, and so life was... lonely, after that. And I don't think.... I wasn't very good at letting people in, either. And I chose pretty badly, which didn't help."

Vague memories of Jonas Hanson crossed his mind, and he had to agree with that one – unbalanced guy, hurt little girl.... It was a bad combination.

"Not a day went by that I didn't wish things were different. I always thought that... if she'd lived, my life would be so different. Better."

The breath he'd been holding came out as a sigh. Now she knew. And she might have been right – given the option, he was pretty sure he knew which she'd prefer, anyway, and he couldn't begrudge her that. "It's not wrong to want what she has, Carter," he said softly.

Bright blue eyes flickered up to his and held. "I think that's the problem."

Okay, now she'd lost him completely. "Huh?"

"If this had happened five, ten years ago, I would. I would want all that – that life. But things have changed. And it just isn't fair." For the first time, the tears threatened, and Jack pushed out of his chair to sit beside her on the couch, keeping a safe distance between them.

"I could have her back," she said softly. "I could have her back, just like I always wanted... but to do it, I'd have to give up everything I have. What kind of choice is that?"

"It's not, Carter. It was never your choice to make."

"There just ought to be a happy medium!" she cried, leaping to her feet. "Why does it have to be _or_? Everything we do – there's never an _and_. It isn't fair."

"Carter…" He sighed. "If I had a choice, I'd bring Charlie back in a second, even knowing everything it would change after that point – everything it would cost me." She grimaced, and he hesitantly reached out his fingers to tangle in hers. "I'm not saying it would be right. I'm not saying it would turn out better, or that that reality is any more or less valid than this one. But he's my _son_.

"And that's why… why we don't get a choice. Because fate makes us who we are. That Carter is not you – that's not _my_ Carter. But it's okay to miss her. It's even okay to envy that Carter what she has – to wish you were there."

"That's just it," she said softly. "I don't."

"Hmm?"

"I've spent twenty years wishing I were that girl, and now that I've seen it, what it's like… I don't anymore. And I don't... quite know what to do with that. But SG-1's my family now... and I wouldn't give that up for the world."

Slowly, Jack got to his feet. "C'mere."

And when she stepped into his arms, her face nuzzling warm into the side of his neck, his own thoughts echoed the sentiment.

No. Not for the world.


End file.
